Vbulletin Security Bolster

I am using vbulletin 3.6.8 and would like the security bolstering against hackers. I would rather not upgrade my version of vbulletin because i have custom made hacks for this specific version, but it has come to my attention that my database has been cloned and hacked. I would like someone to come into my site with root access and check for vulnerabilities, check for potential shells which could potentially be letting my database get hacked. Simple job for a vbulletin expert.